In my last two jobs, one in the Bay Area and one in Vancouver, my usual schedule has been arrive at 9, take a 45-60min lunch, leave at 5 and I've never had anyone tell me I'm not working enough or producing enough output.
In the Bay Area I’ve always rolled in around 11 and left around 5. Maybe 6 if I really need to get something done. When I worked for a remote company I did maybe 20-25 hours most weeks. Everyone’s always been very happy with my work. I’ve gotten offers for seed funding from founders in exit interviews. Penny pinching your hours is a cargo cult.